This invention relates to timing belt systems, and more particularly, to low noise timing belts for use in such systems.
Excessive noise from copier/printers in working environments has been an irritant to users from the advent of such machines until the present day. One of the major contributors to machine noise has been found to be timing belts where engagement between the teeth of the belts and the pulleys emit noise. As the air pockets between the teeth of the belts and the pulleys are displaced periodically along the lateral direction of motion, the disturbance modulates air in the surrounding areas and generates noise. Noise spectra of a typical timing belt as shown in FIG. 1 indicates that the acoustic energy comes from two areas; (i) the energy at mesh frequency and its harmonics; and (ii) the energy at high frequencies which is a result of impact. The noise level is proportional to a number of things, for example, the volume of the air pockets being displaced and the rate at which they are displaced. The peaks at 630 Hz and 1250 Hz in FIG. 1 are the mesh frequency and the harmonics, respectively. The energy at 2 KHz and above is due to impact of the teeth of the timing belt.